1. Field of the Invention
Embodiments of the present invention generally relate to memory modules and, more specifically, to hybrid or mixed-technology memory modules.
2. Description of the Related Art
Memory systems in computers are typically built from memory modules. An example of a common type of memory module is a Dual Inline Memory Module or DIMM. The most common type of memory module is a DIMM that contains just one type of memory technology known as DRAM.
There are several new forms of semiconductor memory that are currently being developed, some as potential replacements for one-transistor-cell DRAM. Examples are Magnetoresistive Random Access Memory (MRAM), Phase-change memory (also known as PCM, PRAM, PCRAM, Ovonic Unified Memory and Chalcogenide RAM or C-RAM), Ferroelectric RAM (FRAM), Resistor RAM (RRAM), and Molecular Wire Crossbar Memory (MWCM). Most of these new memory technologies have system properties (most notably the read and write bandwidth and read and write latency) that are different from DRAM. In addition there are several flash memory technologies, such as NAND and NOR flash, that are attractive (because of their high density and low cost) for use as system memory, but again have system properties that are different from DRAM. Therefore, an ideal memory module would incorporate different types of memory while having a single memory interface with a host computer.
As the foregoing illustrates, what is needed in the art is a mixed-technology memory module architecture that combines different memory technologies while presenting a single, preferably standard, technology interface.